B Reactor – the showplace of the Manhattan Project National Historical Park

B Reactor Museum Association

Richland, Washington, USA

BRMA tour guides

B Reactor Awaits You

About B Reactor

B-Reactor, the world’s first industrial-scale nuclear reactor, was built during World War II as part of the top-secret Manhattan Project to develop the atomic bomb. One of three plutonium production reactors built in total secrecy at Hanford during World War II, B Reactor produced plutonium for the Trinity test at Alamagordo, New Mexico, on July 16, 1945, and for the atomic bomb exploded on Nagasaki on August 9, 1945.

B Reactor is included in the Manhattan Project National Historical Park, consisting of historic facilities at Hanford, Los Alamos and Oak Ridge, which was authorized by Congress in December 2014. A memorandum of agreement between the National Park Service and the Department of Energy has been drafted to define their respective roles in managing the park.